13.21 Highlights of What’s New in Version 34.4.0

Here is a summary of what’s changed since release 34.3.0.

13.21.1 Bug Fixes for Elements

• The FTABLE method for integration through 3D magnetic field maps now works in the BRAT element via the USE_FTABLE control. Previously, the control existed but resulted in no transformation of particles taking place.
• The YAW and PITCH parameters of the LTHINLENS and LMIRROR elements were overwriting the TILT parameters of the same elements.
• The B7 and B8 parameters of the CSRCSBEND elements were overwriting the B6 parameter of the same element.

13.21.2 Bug Fixes for Commands

• The share_tracking_based_matrices feature, controlled by the global_settings command, now works correctly. This can provide a considerable increase in performance when tracking-based matrices are required for many beamline elements.
• The insert_sceffects command and SCMULT element, used for space-charge simulation in rings, had a bug that caused the sign of the tune shift to be wrong for protons and positrons. This was reported by forum user hongjin.

13.21.3 New and Modified Elements

• MARK elements with FITPOINT=1 now create psix and psiy symbols for use in optimization, in addition to nux and nuy. This may be more intuitive for some users, as pointed out by forum user jgarland.
• When used for longitudinal feedback, the TFBDRIVER element now includes simulation of the feedback cavity resonance and driving circuit, using a circuit model developed by T. Berenc (APS).
• When K. Hwang’s fringe model is used for the CSBEND element, automatic adjustment of the FSE value can optionally be invoked in order to null out trajectory errors that result from the fringe fields extending outside the magnet. This is obtained by setting FSE_CORRECTION=1.
• The TRACKING_MATRIX parameter of CSBEND can now be used to control the order of the tracking-based matrix, with a limit of third order. This provides an alternative to the 2nd-order analytical matrix.
• The CSBEND element now supports separate edge integral values for the entrance and exit fringes, using the FINT1 and FINT2 parameters. If not given, the FINT parameter is used as before.
• The CSBEND and CSRCSBEND elements now support a new symplectic edge effects mode, based on the linear approach of K. L. Brown. It is similar to the existing, non-symplectic default mode, but in most cases users won’t see a difference.
• The CSBEND, KQUAD, KSEXT, KOCT, KQUSE, and MULT elements now support use of the expanded (to leading order) Hamiltonian by setting the EXPAND_HAMILTONIAN flag to 1. Note that no significant reduction in run time is observed with the expanded Hamiltonian.

13.21.4 New and Modified Commands

• None.

13.21.5 Changes Specific to the MPI Parallel Version

• None.

13.21.6 Changes Specific to the GPU Version

The GPU version continues to be an alpha release and contains bugs. Users are encouraged to check results against the serial or parallel versions and report issues to the developers.

• None.

13.21.7 Changes to Related Programs and Files

• The FTABLE method for integration through 3D magnetic field maps now works in the abrat program via the -ftable commandline option. Previously, the control existed but resulted in no transformation of particles taking place.
• The program abrat now places the vertex, entry, and exit points (which are provided by the user) in the trajectory output file.